In order to analyze and predict the thermal conductivity of full grade coal gangue concrete, nine groups of tests were designed with five different substitution rates of coarse gangue aggregate (0, 25%, 50%, 75%, 100%) and four different substitution rates fine gangue aggregate (25%, 50%, 75%, 100%). The results show that the higher the replacement rate of coal gangue coarse aggregate is, the lower the thermal conductivity of concrete will be; when the replacement rate of coal gangue coarse aggregate is 100%, the thermal conductivity of coal gangue concrete will continue to decrease with the increase of the replacement rate of coal gangue fine aggregate, among which the thermal conductivity of full grade coal gangue concrete is the lowest, which is 52.56% lower than that of ordinary concrete; coal gangue aggregate impact factor M is defined, and the larger the M, the lower the thermal conductivity of concrete is; the modified calculation model of thermal conductivity of coal gangue concrete is obtained by modifying the Hasselman-Johnson thermal conductivity calculation model, and the modified calculation results are in good agreement with the test values.